Research On Base Station Deployment Method Of Ground-based Pseudolite System

The ground-based pseudolite positioning system is a regional wireless positioning system,it can provide high-precision positioning service in the area where the Global Navigation Satellite System(GNSS)signal cannot be covered.The base station distribution is critical when deploying pseudolite base station,because it has a great influence on the positioning accuracy of pseudolite positioning system,it means pseudolite positioning system will have unsatisfactory positioning accuracy or even impossibly position in a bad pseudolite base station distribution,therefore,this paper studies the base station deployment method of ground-based pseudo-satellite positioning system.The paper discusses relationship between pseudolite base station distribution and positioning accuracy based on principle of the wireless positioning algorithm,and analyzes the difference between the ground-based pseudolite positioning system and the GNSS in error source.According to the error analysis,we propose a more suitable evaluation index for the base station distribution of ground-based pseudolite system based on the evaluation index of satellite distribution in GNSS,and summarize the basic guidelines for the distribution of pseudolite base stations by simulation.In practical applications,the ground-based pseudolite positioning system has different application situations,the optimal pseudolite base station distribution in each situation is different,if the grid traversal method is used to search for optimal layout of base stations,the computational complexity will be too high.In order to solve this problem,a pseudolite base station deployment method based on improved genetic algorithm is proposed for the situations with good visibility,it is proved that the algorithm has good convergence performance and can adapt to different pseudolite application situations.For the situations with bad visibility,the station distribution problem becomes more complex,the distribution of the base station should not only ensure positioning accuracy,but also ensure the signal coverage rate.Therefore,this paper applies visual domain analysis technology and digital elevation model to calculation of the signal coverage rate,meantime,a pseudolite base station deployment method based on non-dominant sequencing genetic algorithm(NSGA-II)with elite strategy is proposed,which uses signal coverage rate and positioning accuracy as the optimization goal.Finally,simulation of mountainous terrain in Zhangjiajie is carried out,the results show that this method can effectively improve the signal coverage rate and ensure the positioning accuracy.Besides,a visible pseudolite base station distribution software is designed,the results of this paper is verified by using the pseudolite positioning system in the actual environment of the terminal,the results show when pseudolite is deployed according to the station deployment method of this paper,the pseudolite system can reach the desired positioning accuracy.This paper can provide some ideas for the pseudolite system in various situations.